Residues of volatile halocarbons in margarines.

Findings of residues of volatile halocarbons (VHCs) such as 1,1,1-trichloroethane, trichloroethylene and tetrachloroethylene in margarine are reported. VHCs were determined by a headspace gas chromatographic method with electron capture detection. Identity was confirmed by headspace gas chromatography-mass spectrometry for some of the higher level (100-5000 ppb) residues. A total of 70 stick, soft and diet soft margarines were purchased in the Washington, DC, metropolitan area. In addition, margarines and margarine ingredients were collected from 19 production lines. These products plus the adhesives used in the packaging were examined. Levels of VHCs ranging from 5 to 100 ppb (ng/g) were found in many of the margarines. The highest concentrations of any individual VHC (tetrachloroethylene at 1-5 ppm) were found in margarines obtained from a supermarket located next to a dry cleaner. Possible sources of VHC residues are discussed.